Field of the Invention
The present invention relates to a tire provided with an information acquisition device for transmitting information by radio waves using a coil-shaped antenna; more specifically, the present invention relates to a tire in which attenuation of transmitted radio waves from an information acquisition device is reduced.
Background Information
In vehicles, it has conventionally been very important to check and manage the air pressure in the tires, and cases where the tire air pressure reaches an abnormal value have very often been the cause of accidents happening. For this reason, there has been known a tire status monitoring system (for example, see Patent Literature 1) in which each wheel is provided with a tire information acquisition device for detecting the air pressure inside the tires of the wheels and transmitting information thereto, the system being provided with a monitoring device for acquiring the information relating to the tire air pressure transmitted from each of the tire information acquisition devices and for monitoring the air pressure in each of the tires and emitting an alarm whenever there is any abnormality in the air pressure.
The tire information acquisition devices in this tire status monitoring system are disposed in an interior space formed between the tire and the wheel. The tire information acquisition device has a case adapted to house, inter alia, an air pressure sensor including a pressure detection element for detecting the air pressure inside the tire, as well as a transmitter for converting the detection result from the air pressure sensor to an electric signal and transmitting same to the monitoring device wirelessly. The case is provided with a vent hole whereby the air inside the interior space formed between the tire and the wheel is to be introduced to the air pressure sensor of the interior. The monitoring device is disposed in the vicinity of the driver seat. The monitoring device receives the air pressure information relating to the tires as transmitted from the tire information acquisition devices, and generates a predetermined alarm for the drive in a case where the air pressure in a tire is lower than a predetermined reference pressure.
[Conventional Art Literature]
[Patent Literature]    [Patent Literature 1] Japanese Patent No. 3962073